Syrian activists say rebels and government troops are fighting for control of a key airbase in the country’s north.

The Syrian Observatory for Human Rights says the rebels have launched a dawn offensive to take Taftanaz air base, a day before a crucial opposition conference in Qatar.

Taftanaz lies near the highway between the capital Damascus and the northern city of Aleppo, a major front in the civil war.

Activist videos posted online claim to show the attack on Taftanaz. A rebel vehicle fires rockets and smoke rises over buildings and what appears to be an airstrip. The videos appear genuine and are consistent with other Associated Press reporting in the area.